Dynamic Random Access Memory (DRAM) is a data storage device that is used in many different types of computational devices. Some DRAM chips are comprised of rectangular arrays of memory cells referred to as banks. Each bank has support logic that is used for reading and writing data in the bank, and refresh circuitry to maintain the integrity of the data stored in the bank. The banks may operate independently but may share command, address, and data pins. Each bank may be comprised of a hierarchical structure with rectangular arrays of memory cells. The contents stored in memory cells are addressed via word lines and bit lines. The intersection of a word line and a bit line constitutes the address of a memory cell.